The television viewing experience has been enhanced in recent years through the ability of providers to provide additional information to the viewer. An electronic program guide information (EPG) allows a user to easily identify upcoming programming, provides additional information about programming and allows a user to accomplish additional tasks such as setting a recording time. EPG data is typically transmitted in band or out of band with the distribution mechanism of the service.
Entertainment services, including broadcast television, audio programming and data, may be provided to users using one of a number of digital transmission schemes. Digital Video Broadcasting (DVB) is a set of standards that define digital broadcasting using existing satellite, cable, and terrestrial infrastructures. There are several types of transport schemes, including transport satellite (DVB-S, DVB-S2 and DVB-SH); cable (DVB-C); terrestrial television (DVB-T, DVB-T2) and digital terrestrial television for handhelds (DVB-H). Integrated Services Digital Broadcasting (ISDB) is the digital television and digital radio format that Japan has created to allow radio and television stations there to convert to digital. ATSC is a digital television format which will replace the analog NTSC system in the United States.
In each of these transportation systems, each digital transport stream typically contains multiple services or channels, and also carry the associated EPG data. Digital receivers which receive, decode and output these services to a video or audio equipment need to scan available streams on a regular basis to keep EPG data up to date. A full scan on all transponders or multiplexes can take minutes for a DVB-T receiver but can take much longer for other receivers such as ISDB-T and DVB-S. In the case of DVB-S a scan algorithm may take several hours to complete.
When a Digital TV service list and the program guide are out of date, they adversely impact the end user experience.